The definition of Light Reflective Value (LRV) is the percentage of light something reflects, this can be affected by the colour and texture of an item. White would be 100% as it reflects 100% of the light, whereas black would be considered 0% as it reflects none of the light. Light Reflective Value is used to predict how light or dark something will appear, and therefore how easy it will be to see it.
How is the Light Reflective Value measured?
Predominantly, light reflective values are measured using spectrophotometer, tristimulus colourimeter, or other reflectometer, such as an integrating sphere.
At CAT we use an integrated sphere spectrophotometer to test the product finishes, to ensure that the products we provide to our clients adhere to regulations and LRV standard guidance.
You can also find the LRV for our Stair Nosings on our technical data sheets for all of our tread inserts and their colours.
Why is it important to measure the LRV when installing Stair Nosings?
One of the most important reasons behind measuring the LRV and ensuring you are adhering to regulations is so that people who are partially sighted can see the contrast in where one step ends and the one below begins. If there is not a 30-point difference, then it makes it a lot more difficult for people who are partially sighted to see the contrast in stair edge. Utilising a stair nosing and infill that offer the correct amount of contrast means that you make it safer, and you are adhering to regulations.
This is relevant to a wide range of non-residential buildings including, hospitals, schools, hotels, theatres, etc.
What is the specific current guidance/regulations?
The current guidance in the regulations BS8300:2009 is that adequate visual contrast is provided if the Light Reflectance Value (LRV) of the contrasting areas exceeds 30 points, “i.e., the contrast between the stair edging and the floor covering”.
For example, there should be a 30-point different between the flooring and the stair nosings, so if your flooring has an LRV of 60, then your stair nosing must be either 0-30 or 90-100, which will create enough contrast for the step to be more visually clear.

Installation Example: A polished Aluminium Stair Nosing with LRV 75.55 installed with a Castellated PVC Infill in White, with LRV of 84.22 on a flooring with an LRV of 32 would comply with the regulation, as the difference between the stair nosing, including the infill and your chosen flooring is greater than 30 points.